Tennis racket



Oct. 16!

R. H. ROBINSON TENNIS RACKET Filed Aug. 28

Patented Oct. 16, 1923.

ROY H. ROBINSON, OF CHICAGO, ILLINOIS.

'TENNIS nnennfr.

Application led August 28, 1922.

70 all whom t may concern.'

Be it known that IE ROY H. ROBINSON, a citizen ot the United States,residing in Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Tennis Rackets, of whichthe Atollowing is a specification.

This invention relates to rackets tor lawn tennis, but more particularlyto such as are provided with a metal trame, and has for its primaryobject to produce a trame construction o this type which will no-t cutthe strings of the racket.

Further objects are to provide an improved method of Stringing theracket, to permit adjustment of the sti-inging in the racket. and ingeneral to provide an iinproved racket.

Metal tennis racket Ytrames are preferable to the present wooden typebecause of their greater strength and reduced air resistance. The onlyserious disadvantage of this type et Ytrame has been the 'frequentcutting of the strings. Tire strings have been tried as a substitute forthe usual gut but these have less resiliency and are also cut by themetal edges, although less quickly than the gut.

In order to obviate the disadvantages and retain the advantages of themetal trame racket, I have provided the Jframe with a` cushioningelement which prevents the strings from coming in contact with themetal. Also I have provided a new method ot' Stringing which eliminatesthe sharp bearing angles tor the strings on the frame. My improvedstringing likewise distributes the blows on different strings throughoutthe longitudinal zone et impact which in the present type ot' acketstall principally on the central longitudinal strings. The adjustabilityot the trame permits the Stringing to be tightened or slackened at willand is particularly advantageous because it relieves the strain upon thestringing when the racket is not in use and permits the tension to loevaried in accordance. with weather and other conditions.

The many other objects and advantages et my invention will be betterunderstood by reference to the following specification when consideredin connection with the acempanying drawing illustrating certain selectedembodiments thereoin which:

Fig. 1 is a front elevation of the racket.

Serial No. 584,619.

Fig. T illustrates a modified form of Stringing.

Referring to the drawing and particularly to Figs. 1 to et. the racketcomprises a trame 10 provided with the usual. handle 11 and sti-inging9. The trame 10 varies somewhat in form in various models of raf het butis substantially oval in shape and is provided with a shank 12 uponwhich the handle is secured. The particular desifrn ot racket 'trameillustrated in Fig. 1 oi the drawing is similar to that ot a wellltnownmake in which the trame is tubular in form. The shank 12 is formed ot apair ot' tubes 13 which have their outer ends welded to the frame 10.The handle 11 is et wooden construction and is driven upon the tubes 13..i metal ferrule 14 envelops and supports the forward end et the handle11. In my improved construction the metal Jframe 10 is indented in itsouter tace to form a longitudinally extending fhannel 15 within whichlits a cushioning strip 16 et leather. fiber, or other suitablematerial. The outer side of the metal tubing. which alone carries theStringing 9.

'is initially slitted at 1T in the manner indicated in Fig. 4: and theprongs 17 rounded downwardly to provide a smooth bearing surface.havingno sharp edges or angular turns to eut the gut strings. The insidewall T ot the tubular training is longitudinally slotted at intervals asat S to permit the strings to pass inwardly and outwardly withoutcontacting therewith. The cushion 1.6 slitted in substantially the samemanner as the upper or outer wall ot the tube and maintains the stringsout ot contact therewith. as indicatedV in Fig. 2. It wire sti-inging isused the cushioning element might be omitted as the rounded bearingsurfaces would vnot cut this material.

Instead ot Stringing the racket in the usual manner with the stringsextending llU fifi

longitudinally and transversely of the frame, I have provided a new iormoit Stringing in which the strings run obliquely ot the trame. This formof Stringing has many advantages which make it preferable for eitherwood or metal frame racket-s, but in the case oit metal trame raclietsit is particularly desirable because each string as it passes throughthe traine is merely turner through au angle ot about 41:5 degreesinstead making a complete turn or reversal ot direction. It has beenfound in practice that practically all the impacts of the ball occur ina central strip extending longitudinally ot the rachet so that in thepresent type ot racket a gtew of the longitudinal strings receivepractically all of the impacts and it is these strings which usuallybreak i'irst. In my improved form ot oblique stringing these impacts aredistributed over practically all the strings. Furthermore, the stringsreceiving the majority et impacts are shorter in length than in thepresent type of bracket. In the majority ot strolqcs the racket iscaused to strike the ball a glancing blow which usually occurs approxi--inately along the lateral axis ot the rachet or at a right angle to thelongitudinal strings and parallel'tothe lateral strings in the 'form otStringing hitherto employed. '.lhe object of this is to produce a spinupon the hall. The amount oit spin depends upon the 'friction created bythe contact ot the bail with the strings of the racket. lthas been foundthat my improved form ot stringing very materially increases thetrictional resistance and thus proportionally increases the spin.Another advantage of my oblique Stringing is that it permits thetightening or loosening et' the strings by the adjusting ot the size otthe iframe which would not be possible in the present form ot stringing.

In order to make possible the adjustment of' the rachet frame to eithertighten or loosen the stringing, I have provided in the 'trame smallturn-buckles 18 consisting ot an interim-ly threaded -ive 19 littingupon op positcly threaded screws 2li set in the fijfposiug en( s ot thetrame. The sleeve 'i9 preferably of substanl'ially the same ci;- leriorsize as the metal tubing ot the bracket. The s 1e ve 2l) is providedwith ay series or' perforations to permit it to be turned by a small pinor lcey. lllheu these turn-buckles are located at the top and bottom otthe trame, as indicated in Fig. l, each side oi the rachet iorms anarch, and when this is pushed outwardly by the screws the strings arenot only tightened but the tightening ot the `nearest strings :torcesout the arch in the rei Yer until an equilibrium in the. tightening o t'all et the strings is reached. It only one turn-buckle is to be used it`is advisable that this belocated at the bottom or handle end of the`frame so that the trame may be contracted or spread at this point. Thespreading ol the lower arch ot the racket tightens both sets of stringsat their .lower end and accordingly the entire stringing ot the rachet.Any other well-known method ot adjusting the size ot the traine may beused in place ot the tiun-buclilc described. lnstead ol placing theadjusting elements at the top and bottom ot the iframe, or at either otthese locations, the adjusting elements may be placed on opposite sidesoit the racket and this form is advantageous where more longitudinallyoblique stringl is used. The oblique Stringing and the adjustment oi?the trame are equally applicable to both metal and wooden `tramerachetfli, as will be readily evident.

Instead ot using a tubular metal trame, such as has been described inconnection with Figs. l to al inclusive, a braced troughshaped trame 30,such as is shown in Figs. 5 and 6, may be used. In this` trame the sidemembers Si join in a comparatively sharp edge 32 and the outer edges otthese sides are prete ably rolled over at 3i-l. Metal ties 3ft connectthese outer edges at suitable intervals and properly brace the trame. Aliller oit' tiber, wood, leather, or other suitable material, is placedwithin the trough and is held in place therein by the outer rolled edgesthereof. This tiller is punched or cut away, as at 36, to permit thepassage ot the strings therethrough and iorms the cushion for thesestrings in the same manner as the strip 16 in the previous embodiment.This form of frame is not only neat in appearance but its concave facescoming to a substantially sharp edge between the stringing con torni well to the ball and practically eliminate what is linown as wood shots.The playing area of the rachet is extended practically to the outer edgeor the frame.

Instead of the form ol' single Stringing illustrated in Fig. l, thestrings may be grouped in pairs with a slight interval between thesprings in each pair, in the manner indicated at l() in Fig. 7. Thistorm ot stiinging is advanlageous, as it provides larger openings Jr-lfor the ball to sink into without reducing the number oli strings.

lVith my improved form ol racket it is possible to use gut Stringing andthe strings will not be cut by the metal ot the trame. The oblique form0l Stringing increases the playing efficiency ot the racket and thewearing qualities of the same. It also makes possible the adjustment ofthe trame with the benefits set forth.

I am aware that many changes may be made in the construction andarrangement olparts without departing from the spirit of my invention,and I reserve the right to make all such as lfairlyv tall within thescope oit the following claims.

I claim as my invention:

l. A tennis rachet comprising a substantially oval shaped tubular metalframe having a channel formed in its periphery and extendinglongitudinally thereof, a strip of yielding material fitting Within saidchannel, stringing woven through said frame and said strip, and a handleconnected to said traine.

2. A tennis racket comprising a tubular frame having its outer wallslitted at inter vals and the metal pressed inwardly to form a series ofstring-bearing surfaces, a handle connected to said frame, and Stringingpassing through the inner wall of said 'trarne and about the bearingsurfaces on said outer Wall.

3. A tennis racket comprising a tubular frame having a series oflongitudinally spaced slots formed in its inner wall and its outer wallslitted at longitudinal intervals with the metal turned inwardly to forma series of rounded string-bearing surfaces, a handle connected to saidframe, and stringing passing through the slots in the inner wall of saidtrame and about the corresponding string-bearing surfaces on the outerwall thereof.

Il. A tennis racket comprising a substantially oval shaped frame dividedtransversely on the longitui'linal axis thereof` au adjusting elementdisposed between the opposing ends of said trame, a handle Connected tosaid frame, and stringing woven through said frame.

5. A tennis racket comprising a substantially oval shaped frame dividedtransversely on the longitudinal axis thereof, a turn-buckle connectingthe opposing ends @t said frame, a handle connected to said trame, andStringing woven through said frame.

6. A tennis racket comprising a substantially oval-shaped frame having achannel therein and extending longitudinalhv thereet, a strip otyielding material fitting within said channel and retained therein bythe conformation ot' the walls ot' the channel, stringing woven throughsaid frame and said strip, and a handle connected to said frame.

7. A tennis racket comprising a metal traine having a series ofsubstantially H- shaped slits provided therein and the prongs formed bysaid slits pressed inwardly. a

handle connected to said frame, and stringing passing through theOpenings formed by said slits.

8. A tennis racket comprising a tubular metal frame having a series ofslots formed in its inner wall and its outer wall provided withcorresponding substantially H-shaped slits, said outer wall beingindented t0 provide a longitudinal channel therein and having the prongsformed by said slits bent inwardly, a strip of yielding materialextending longitudinally of said frame within said channel and slittedt0 correspond with the Wall thereof, Stringing woven through said :trameand said strip, and a handle conneeted to said frame.

9. A tennis racket comprising a substantially oval-shaped frame dividedtransversely at opposite points, adjusting elements located at each ofthe points ot' division, a handle connected to-Said frame and Stringingwoven through said fra-me.

l0. A tennis racket comprising a substantially oval-shaped frame,Stringing woven through said frame with one Set of strings disposed atan angleto the other set, an adjusting element incorporated in saidframe between said sets ol strings, the strings oleach set engaging theframe on opposite sides of said element and a handle connected to saidframe.

l1. A tennis racket comprising a frame having an open throat, anadjustable member forming the sole connection between the sides of theframe at the throat, a handle connected to the ends of the traine, andStringing woven through said frame.

l2. A tennis rachet comprising a substantially oval-shaped trame,obliquely arranged Stringing woven in said frame, means disposed betweenthe sets of Stringing for adjusting said frame to vary the tension ofsaid Stringing, the strings of each set engaging the frame on oppositesides ot said means and a handle connected to said frame.

13. A tennis racket comprising a substantially oval-shaped metal framehaving pertorations therein to admit the Stringing, Stringing woventhrough said pei-iterations. cushioning means interposed between saidStringing and said frame and retaining said Stringing out et contactwith said frame. and a handle connected to said frame.

ROY l-l. ROBINSON.

